Effect of butylated hydroxytoluene supplementation on ultrastructure of crossbred bovine spermatozoa

Abstract

The present study was planned to observe the effect of Butylated hydroxytoluene (BHT) on ultra structure changes in bovine crossbred spermatozoa. The sperm plasma membrane is the primary site of damage induced by cryopreservation. There are many harmful conditions such as cold shock, osmotic stress, ice crystal formation or oxidative damage etc which cause sperm cryo-injury and loss of sperm viability and fertility during cryopreservation. At the time of cryopreservation there were considerable ultra structure changes to the acrosomes and middle piece studied by transmission electron microscopy. Semen from two crossbred bulls were collected and extended with egg yolk tris dilutor along with addition of different concentrations of BHT i.e. 0.0mM (Control), 0.5mM (T 1 ) and 1.0mM (T 2 ), respectively. The effect of BHT on ultrastructural alterations was revealed by Transmission electron microscopy during post dilution (Stage I), post equilibration (Stage II) and post thaw (Stage III), respectively. TEM results of spermatozoa at Stage I, II and III showed that major ultrastrucural alterations occur in plasma membrane and outer acrosomal membrane. Group T 1 and T 2 showed significantly lower number of ultrastructural defects compared to control at Stage I, II and III. The study indicated that 1.0mM BHT increases the cryosurvival of sperm as revealed by post thaw lower ultrastructural defects of bovine bull spermatozoa